Michael,
I think im going to go down the bolt on riser option, i fitted them to Liz's XBR a number of years ago as she needed a more upright riding position and it was a fairly simple mod, shame we sold her bike!!. Im just looking to change the tank, saddle and tail unit and fancy an upright riding style, all of which will be done on a very tight budget!! i only thought there may have been a yoke that i could have just done a straight swap.
G